Merge pull request #1065 from alainmarcel/alainmarcel-patch-1

always transform for Yosys
chipsalliance · Dec 13, 2023 · 0aeb4da · 0aeb4da
2 parents 75fa88b + 54a8c8c
commit 0aeb4da
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Showing 2 changed files with 137 additions and 1 deletion.
diff --git a/templates/SynthSubset.cpp b/templates/SynthSubset.cpp
@@ -28,6 +28,7 @@
 #include <uhdm/clone_tree.h>
 #include <uhdm/uhdm.h>
 #include <uhdm/vpi_visitor.h>
+#include <uhdm/Serializer.h>
 
 namespace UHDM {
 
@@ -480,7 +481,139 @@ void SynthSubset::leavePort(const port* object, vpiHandle handle) {
     serializer_->GetErrorHandler()(ErrorType::UHDM_FORCING_UNSIGNED_TYPE, errMsg,
                                      reportObject, nullptr);
   }
-
+}
+
+// Transform 3 vars sensitiy list into 2 vars sensitivity list because of a
+// Yosys limitation
+void SynthSubset::leaveAlways(const always* object, vpiHandle handle) {
+  if (const UHDM::any* stmt = object->Stmt()) {
+    if (stmt->UhdmType() == uhdmevent_control) {
+      event_control* ec = (event_control*)stmt;
+      if (const any* cond = ec->VpiCondition()) {
+        if (cond->UhdmType() == uhdmoperation) {
+          operation* op = (operation*)cond;
+          VectorOfany* operands = op->Operands();
+          VectorOfany* operands_op0 = nullptr;
+          VectorOfany* operands_op1 = nullptr;
+          any* opLast = nullptr;
+          int totalOperands = 0;
+          if (operands->size() > 1) {
+            if (operands->at(0)->UhdmType() == uhdmoperation) {
+              operation* op = (operation*)operands->at(0);
+              operands_op0 = op->Operands();
+              totalOperands += operands_op0->size();
+            }
+            if (operands->at(1)->UhdmType() == uhdmoperation) {
+              operation* op = (operation*)operands->at(1);
+              opLast = op;
+              operands_op1 = op->Operands();
+              totalOperands += operands_op1->size();
+            }
+          }
+          if (totalOperands == 3) {
+            any* opMiddle = operands_op0->at(1);
+            if (opMiddle->UhdmType() == uhdmoperation &&
+                opLast->UhdmType() == uhdmoperation) {
+              operation* opM = (operation*)opMiddle;
+              operation* opL = (operation*)opLast;
+              if (opM->VpiOpType() == opL->VpiOpType()) {
+                // Transform: always @ (posedge clk or posedge rst or posedge
+                // start)
+                //              if (rst | start) ...
+                // Into:
+                //            wire \synlig_tmp = rst | start;
+                //            always @ (posedge clk or posedge \synlig_tmp )
+                //               if (\synlig_tmp ) ...
+
+                any* midVar = opM->Operands()->at(0);
+                operands_op0->pop_back();
+
+                // rst | start
+                operation* orOp = serializer_->MakeOperation();
+                orOp->VpiOpType(vpiBitOrOp);
+                orOp->Operands(serializer_->MakeAnyVec());
+                std::string_view var2Name = midVar->VpiName();
+                orOp->Operands()->push_back(midVar);
+                std::string_view var3Name = opL->Operands()->at(0)->VpiName();
+                orOp->Operands()->push_back(opL->Operands()->at(0));
+
+                // posedge clk
+                operands->at(0) = operands_op0->at(0);
+
+                // wire \synlig_tmp = rst | start;
+                cont_assign* ass = serializer_->MakeCont_assign();
+                logic_net* lhs = serializer_->MakeLogic_net();
+                std::string tmpName = std::string("synlig_tmp_") + std::string(var2Name) + "_or_" + std::string(var3Name);
+                lhs->VpiName(tmpName);
+                ass->Lhs(lhs);
+                ref_obj* ref = serializer_->MakeRef_obj();
+                ref->VpiName(tmpName);
+                ref->Actual_group(lhs);
+                ass->Rhs(orOp);
+                const any* instance = object->VpiParent();
+                if (instance->UhdmType() == uhdmmodule_inst) {
+                  module_inst* mod = (module_inst*)instance;
+                  if (mod->Cont_assigns() == nullptr) {
+                    mod->Cont_assigns(serializer_->MakeCont_assignVec());
+                  }
+                  bool found = false;
+                  for (cont_assign* ca : *mod->Cont_assigns()) {
+                    if (ca->Lhs()->VpiName() == tmpName) {
+                      found = true;
+                      break;
+                    }
+                  }
+                  if (!found)
+                    mod->Cont_assigns()->push_back(ass);
+                }
+
+                // posedge \synlig_tmp
+                opL->Operands()->at(0) = ref;
+
+                // if (\synlig_tmp ) ...
+                if (UHDM::scope* st = any_cast<scope*>(ec->Stmt())) {
+                  VectorOfany* stmts = nullptr;
+                  if (st->UhdmType() == uhdmbegin) {
+                    stmts = any_cast<begin*>(st)->Stmts();
+                  } else if (st->UhdmType() == uhdmnamed_begin) {
+                    stmts = any_cast<named_begin*>(st)->Stmts();
+                  }
+                  if (stmts) {
+                    for (auto stmt : *stmts) {
+                      expr* cond = nullptr;
+                      if (stmt->UhdmType() == uhdmif_else) {
+                        cond = any_cast<if_else*>(stmt)->VpiCondition();
+                      } else if (stmt->UhdmType() == uhdmif_stmt) {
+                        cond = any_cast<if_stmt*>(stmt)->VpiCondition();
+                      } else if (stmt->UhdmType() == uhdmcase_stmt) {
+                        cond = any_cast<case_stmt*>(stmt)->VpiCondition();
+                      }
+                      if (cond->UhdmType() == uhdmoperation) {
+                        operation* op = (operation*)cond;
+                        if (op->VpiOpType() == vpiBitOrOp) {
+                          VectorOfany* operands = op->Operands();
+                          if (operands->at(0)->VpiName() == var2Name &&
+                              operands->at(1)->VpiName() == var3Name) {
+                            if (stmt->UhdmType() == uhdmif_else) {
+                              any_cast<if_else*>(stmt)->VpiCondition(ref);
+                            } else if (stmt->UhdmType() == uhdmif_stmt) {
+                              any_cast<if_stmt*>(stmt)->VpiCondition(ref);
+                            } else if (stmt->UhdmType() == uhdmcase_stmt) {
+                              any_cast<case_stmt*>(stmt)->VpiCondition(ref);
+                            }
+                          }
+                        }
+                      }
+                    }
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
 }
 
 }  // namespace UHDM
diff --git a/templates/SynthSubset.h b/templates/SynthSubset.h
@@ -62,6 +62,9 @@ class SynthSubset final : public VpiListener {
   // Apply some rewrite rule for Yosys limitations
   void leaveFor_stmt(const for_stmt* object, vpiHandle handle) override;
 
+  // Apply some rewrite rule for Yosys limitations
+  void leaveAlways(const always* object, vpiHandle handle) override;
+
   // Apply some rewrite rule for Synlig limitations
   void leaveRef_typespec(const ref_typespec* object, vpiHandle handle) override;